perf(render): bound animation and alpha scratch residency

Complete Slice D3 by replacing the unbounded animation dictionary with a concurrent byte/count LRU and by putting the three retail alpha scratch owners behind one typed aggregate budget. Preserve immediate growth and draw order while reclaiming one-frame density spikes after sustained under-use. Close stale bounds-cache issue evidence without inventing a cache.

src/AcDream.App/Composition/LivePresentationComposition.cs

@@ -5,6 +5,7 @@ using AcDream.App.Input;
 using AcDream.App.Interaction;
 using AcDream.App.Physics;
 using AcDream.App.Rendering;
+using AcDream.App.Rendering.Residency;
 using AcDream.App.Rendering.Selection;
 using AcDream.App.Rendering.Sky;
 using AcDream.App.Rendering.Vfx;
@@ -586,6 +587,9 @@ internal sealed class LivePresentationCompositionPhase
     {
         LivePresentationDependencies d = _dependencies;
         WorldRenderFoundation foundation = world.Foundation;
+        AlphaScratchBudgetProfile alphaScratchBudgets =
+            AlphaScratchBudgetProfile.Create(
+                d.Options.ResidencyBudgets.AlphaScratchBytes);
 
         var selectionScene = new RetailSelectionScene(
             new RetailSelectionGeometryCache(content.Dats, d.DatLock));
@@ -601,7 +605,8 @@ internal sealed class LivePresentationCompositionPhase
                 d.ClassificationCache,
                 d.TranslucencyFades,
                 selectionScene,
-                d.RetailAlphaQueue),
+                d.RetailAlphaQueue,
+                alphaScratchBudgets.DispatcherBytes),
             static value => value.Dispose());
         var selectionQuery = new WorldSelectionQuery(
             liveEntities,
@@ -883,7 +888,8 @@ internal sealed class LivePresentationCompositionPhase
                 foundation.TextureCache,
                 content.Dats,
                 foundation.MeshAdapter,
-                d.RetailAlphaQueue),
+                d.RetailAlphaQueue,
+                alphaScratchBudgets.ParticleBytes),
             static value => value.Dispose());
         Fault(LivePresentationCompositionPoint.SkyAndParticlesCreated);
 
@@ -966,6 +972,19 @@ internal sealed class LivePresentationCompositionPhase
             frameDiagnostics,
             bindings,
             landblockLoaded);
+        foundation.Residency.RegisterDomainSource(
+            new DelegateResidencyDomainSource(
+                ResidencyDomain.AlphaScratch,
+                () => new ResidencyDomainSnapshot(
+                    ResidencyDomain.AlphaScratch,
+                    EntryCount: 3,
+                    OwnerCount: 3,
+                    Charges: new ResidencyCharges(
+                        ScratchBytes: checked(
+                            d.RetailAlphaQueue.RetainedScratchBytes
+                            + dispatcherLease.Resource.RetainedAlphaScratchBytes
+                            + particleLease.Resource.RetainedAlphaScratchBytes)),
+                    BudgetBytes: alphaScratchBudgets.TotalBytes)));
         _publication.PublishLivePresentation(result);
 
         liveRuntimeLease.Transfer();